Molecular Genetics Flashcards Preview

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Flashcards in Molecular Genetics Deck (15):
1

Which of the following statements about DNA annealing is false?

pairing hydrogen bonds to complementary sequence, prevent bonds from reforming, single-strand binding proteins bind to exposed strands of DNA to block the hydrogen bonds from reforming

2

The nucleotide at the end of one strand of a fragment of double-stranded DNA has a free phosphate attached to the 5’ carbon of its deoxyribose sugar. The complementary nucleotide has:

a hydroxal group attached to the 3’ carbon of its deoxyribose sugar

3

Which of the following statements is false regarding the discovery of the model of DNA…

Friedrich Mieschner – isolated non-protein (puss)
Fredrick Griffith – mouse experiment
Hammerling – algae expirement
Avery, McCarty, MacLeod – destroyed lips, proteins, carbs, nucleic acids = transformation – destroyed DNA = no transformation
Chargraff – A=T, C=G
Hershey + Chase – used radioactive sulfur and phosphorus to tag virus
Rosalind Franklin + Maurice Wilkins – x-ray of DNA
Watson + Crick – made model of DNA, discovered the hydrogen bond

4

During DNA replication, one of the new strands of DNA is synthesized continually, while the other synthesized as a number of separate fragments of DNA that are subsequently linked by DNA ligase. This is because:

DNA polymerase III only synthesizes DNA in the 5’ – 3’ direction

5

An enzyme, which excises a mismatched base in a newly synthesized strand of DNA, is called:

an exonuclease

6

In what order do the following molecules become involved in DNA replication in E. Coli?

Helicase, single-strand binding proteins, primase, DNA polymerase III

7

Which of the following correctly describes the order in which cell components become involved in protein synthesis?

DNA, mRNA, ribosome, tRNA

8

Line A below shows the peptide synthesized after transcription and translation of a piece of DNA. Line B shows the peptide synthesized after a mutation in this piece of DNA.

Proline – arginine – aspartic acid – lysine – alycine
Proline – glutamine – aspartic acid – lysine – glycine
A. base substitution

9

In eukaryotes, introns are removed before mRNA leaves the nucleus because:

they do not code for protein

10

Which is the correct sequence for the enzymes listed in DNA replication?

gyrase, helicase, single-stranded binding proteins, primase, DNA polymerase III

11

Compare the original (right) and copied (left) mRNA sequences below. This change could be a result of:

AUAUUCGGCAAUCCG
AUAUUCCGCAAUCCG
A. point mutation

12

Spliceosomes remove introns from a mRNA. This offers the possibility of control at which of the following levels?

transcription

13

The “Central Dogma” states that the flow of genetic information is in the direction…

DNA, RNA, protein

14

There are three kinds of RNA polymerase in eukaryotes-RNA polymerase I, II and III. RNA polymerase I, II, and III are used, respectively, to transcribe:

rRNA, mRNA, tRNA

15

The function of the cap and poly-A tail is added to mRNA in eukaryotic cells is to…

prevent degradation of the mRNA